Arc welder



Nov. 29, 1938. N L. ANDRus ET AL 2,138,754

ARC WELDER Filed July 9, 1938 [nvmdanr Al. ZLEWELL YN Azvoe us LE0 I GANYA vv ATTOKNEY-$ Patented Nov. 29, 1938 UNITED STATES PATENT-1. OFFICE Application July 9, 1938, Serial No. 218,436

' Claims. (01475-361),

This invention relates to new and useful improvements in arc welders generally, and more particularly to such welders of the alternating current type. I 7

It is now common practice to enclose the usual electric mechanism of arc welders in a suitable metallic casing. These casings are commonly made of steel, and because of the inherent characteristics o'f'such metal, a magnetic material is introduced in the leakage flux path of the transformer. The presence of the steel casing increases the leakage flux because of the lower re luctance path offered by the steel casing, whereby a marked reduction in operating efliciency results, due to the hysteresis and eddy current losses developed in the walls of the casing. Also, because of the hysteresis developed in the walls of the casing, considerable heat is generated, which tends to reduce the operating efliciency for a given design.

We have found that by constructing the. enclosing casing of a non-magnetic material having a high electrical resistance, the eillciency of the transformer is materially increased and heating of its walls is reduced to a minimum. The high resistance of such materials reduces eddy currents and results in greater efficiency. Also, by constructing the casing of a non-magnetic material, such as stainless steel, aluminum, Monel metal, manganese steel, or other metals of a nonmagnetic character, the hysteresis losses in the casing are entirely eliminated.

An object of the present invention, therefore, is to provide an arc, welder having a casing whose walls are composed of a suitable non-magnetic material, whereby hysteresis and eddy .current losses in the walls of the casing are substantially reduced.

A further object of the invention is to provide an arc welder casing composed of non-magnetic material, such as stainless steel, aluminum, Monel metal, or manganese steel, whereby the magnetic flux in the casing is minimized, and whereby the walls of the casing will not tend to heat, thereby resulting in greater emciency.

Other objects of the invention will appear from the following description and accompanying drawing and will be pointed out in the annexed claims.

In the accompanying drawing, there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown as various changes may be made within the scope of the claims which follow. 1

For the sake of clarity, there is illustrated in the accompanying drawing, an electric arc welder shown comprising a suitable base 2 having the usual transformer mechanism, generally indicated by the numeral 3, mounted thereon and comprising a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary. Thetransformer mechanism is enclosed within a metallic casing, generally indicated by the numeral 4.

An important feature of thisinvention resides in the construction of the casing 4; This casing is constructed of a suitable material having non-magnetic qualities, whereby the presence of thecasing around the transformer mechanism increases the efilciency of the transformer over other accepted or well known types of metallic casings now in general use.

Metallic transformer casings, as now commonly constructed,-deve1op hysteresis and eddy current losses, primarilydue to the fact that they are constructed of a magnetic nmateriai such as steel, which has a certain influence upon the electrical characteristics ,of the transformer mechan- The casing 4, as shown on the drawing, is supported on the base 2, and completely encloses the transformer mechanism 3. The transformer mechanism is suitably supported within the casing, and the casing may be provided with a suitable cover 5, whereby access may be had to the interior thereof.

We have found, from actual experience, that stainless steel, aluminum, Monel and manganese steels provide very good materials for transformer casings. All of these metals are nonmagnetic, whereby hysteresis is not developed in the casing walls. This results in increased eiliciency and greater economy, in that loss of current as aresult of the casing heating, is materially reduced. When such metals as stainless steel, Monel and manganese steels are used in the construction of the casing, a relatively higher resistance is offered to eddy currents set up by the transformer, thereby giving added or greater eiliciency.

Stainless steel, aluminum and Monel metal provide very desirable materials for transformer casings, for the reasons hereinbefore stated, and as all of these metals may now be obtained at reasonable cost, their use in the construction of transformer casings does not greatly increase the cost of manufacture thereof. These metals are also rust proof, which is a very desirable feature, in that they do not require painting.

Manganese steel, which also has non-magnetic qualities, may also be used in the construction of the transformer casing with substantially equal results. Manganese steel, however, is not rust proof and therefore requires treating of some kind to render it rust proof, such, for example,

as painting.

The novel transformer casing herein disclosed, has been found very practical in actual use and because of its not heating when the transformer is in use, the useful life of the transformer is prolonged, and, at the same time, an apparatus is provided which is very eflicient and economical in operation.

Another advantage gained by the use of such metals as stainless steel, Monel, and manganese steel is, that because of the relatively greater strength of these metals, the casing walls may be made of relatively thinner material, resulting in a reduction in weight without sacrificing strength, and because of their higher electrical resistance, reduce eddy current and heating losses, whereby efficiency is correspondingly increased.

Aluminum has non-magnetic qualities, and may therefore be successfully used in the construction of transformer casings, because of the absence of hysteresis therein, when thus used.

We claim as our invention:

1. An alternating current arc welding mechanism including a transformer having a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary, and a metal casing enclosing said transformer, said casing being formed of a metal which is relatively nonmagnetic thereby to reduce hysteresis and eddy area? current losses arising in the casing from the heavy leakage flux and increase the efficiency oi the transformer.

2. An alternating current arc welding mechanism including a transformer having a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary, and a metal casing enclosing said transformer, said casing being formed of a metal which is relatively nonmagnetic and which has a relatively high electrical resistance thereby to reduce hysteresis and eddy current losses arising in the casing from the heavy leakage flux and increase the efliciency of the transformer.

3. An alternating current arc welding mechanism including a transformer having a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary, and a metal casing enclosing said transformer, said casing being formed of stainless steel which is relatively non-magnetic thereby to reduce hysteresis and eddy current losses arising in the casing from the heavy leakage flux and increase the efficiency of the transformer.

4. An alternating current arc welding mechanism including a transformer having a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary, and a metal casing enclosing said transformer, said casing being formed of manganese steel which is relatively non-magnetic thereby to reduce hysteresis and eddy current losses arising in the casing from the heavy leakage flux and increase the efficiency of the transformer.

5. An alternating current arc welding mechanism including a transformer having a secondary adapted to furnish heavy welding currents and which is related to the primary in such manner as to provide a relatively heavy flux leakage between the primary and secondary, and a metal casing enclosing said transformer, said casing being formed of Monel metal which is relatively non-magnetic thereby to reduce hysteresis and eddy current losses arising in the casing from the heavy leakage flux and increase the efficiency of the transformer.

N. LLEWELLYN ANDRUS.

LEO J. GANYAW. 

